High density fiber enclosure and method

ABSTRACT

A high density fiber enclosure system includes a chassis, cassette trays, an optional unification clip, cassettes, and an optional trunk cable management system. The chassis, cassette trays, and cassettes are configured such that individual cassettes may be installed, removed, and otherwise positioned for easy access by a user. The unification clip allows two adjacent cassette trays to be connected to one other such that cassette trays move as one unit. The trunk cable management system is designed to organize trunk cables and trunk cable furcation legs as well as relieve strain on the trunk cables and trunk cable furcation legs.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/989,221, filed Aug. 10, 2020, which is a continuation of U.S. patentapplication Ser. No. 16/434,411, filed Jun. 7, 2019 (issued as U.S. Pat.No. 10,768,385 on Sep. 8, 2020), which is a continuation of U.S. patentapplication Ser. No. 15/846,455, filed Dec. 19, 2017 (issued as U.S.Pat. No. 10,317,637 on Jun. 11, 2019), which is a divisional of U.S.patent application Ser. No. 15/188,432, filed Jun. 21, 2016 (issued asU.S. Pat. No. 9,864,158 on Jan. 9, 2018), which is a continuation ofU.S. patent application Ser. No. 14/848,757, filed Sep. 9, 2015 (issuedas U.S. Pat. No. 9,690,065 on Jun. 27, 2017), which claims the benefitof U.S. Provisional Application Ser. No. 62/049,442, filed Sep. 12,2014, the entirety of all of which are incorporated by reference herein.

BACKGROUND OF THE INVENTION

This invention relates to data center management, and in particular highspeed data transport fiber cabling systems. Optical fibers allow fortransmission of communications over longer distances and at higherbandwidths than wire cables. Optical fibers are also advantageous forcommunication systems because signals suffer less loss than wire cablesand are immune to electromagnetic interference. Optical fibers aretherefore often used for high bandwidth, long distance applications. Oneof the primary functions of a data center is to provide connectionsbetween incoming and outgoing optical fiber connections.

As demand for high bandwidth increases, it is advantageous to usesmaller and/or higher capacity adapters to minimize the amount of datacenter rack space needed per optical fiber port. Due to this, many usersof data centers are transitioning to smaller Local Connector adapters(“LC adapters”) or Multi-fiber Push-on/Pull-off adapters (“MPOadapters”). Thus, a rack or enclosure which maximizes the number of LCor MPO adapters may be advantageous. Additionally, it may beadvantageous if a rack or enclosure allowed for replacing LC adapterswith MPO adapters which provide multi-fiber capabilities.

From time to time, maintenance or replacement of the adapters in anoptical fiber system becomes necessary. However, disturbing theconnection between optical fibers may cause a disruption in service overthe optical wire. Therefore, it may also be advantageous to use a rackor enclosure system which disturbs a minimal number of optical fiberconnections during maintenance on other adapters.

SUMMARY OF THE INVENTION

The present invention provides an enclosure to maximize the number ofconnections available per rack space as well as provide for easy,non-disruptive maintenance or replacement of installed optical fibercables.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of the chassis with the front access doorclosed in accordance with an embodiment of the present invention.

FIG. 2 is an isometric view of the chassis with the front access dooropen in accordance with an embodiment of the present invention.

FIG. 3 is an isometric view of the chassis with the front door open andchassis cover removed in accordance with an embodiment of the presentinvention.

FIG. 4 is an isometric view of the chassis with the front door open andcassette trays located in the cord move or change position and cassettereplacement or addition position.

FIG. 5 is an isometric view of the chassis of FIG. 4 with one cassettepartially removed from the front of the chassis.

FIG. 6 is a close-up view of the front portion of the cassette trayrails as indicated in FIG. 5 .

FIG. 7 is an isometric view of the chassis with a unification clipinstalled.

FIG. 8 is a close-up view of an installed unification clip and cassettetray rails as indicated in FIG. 7 .

FIG. 9 is a close-up view of an installed unification clip of FIG. 8with the unification clip partially installed.

FIG. 10 is a close-up view of an installed unification clip of FIG. 8with the unification clip removed.

FIG. 11 is an isometric view of the unification clip from the front inaccordance with an embodiment of the present invention.

FIG. 12 is an isometric view of the unification clip from behind inaccordance with an embodiment of the present invention.

FIG. 13 is a perspective view of a tray guide and cassette tray rails,in which the top cassette tray rail is in the home position, the middlecassette tray rail is in the cord move or change position, and thebottom rail is in the cassette replacement or addition position.

FIG. 14 is a broken perspective view of the tray guide and cassette trayrails of FIG. 13 .

FIG. 15 is a perspective view of the spring protrusion and tray guidedetent.

FIG. 16 is an isometric view of the chassis with the front access dooropen and the cassette trays removed.

FIG. 17 is a partially exploded isometric view of the chassis of FIG. 16.

FIG. 18 is an isometric view of a rack mounting bracket.

FIG. 19 is an isometric view of a rack mounting bracket.

FIG. 20 is an isometric view of a slack management plate.

FIGS. 21A and 21B are isometric views of a slack management platedivider.

FIG. 22 is a partially exploded isometric view of the chassis of FIG. 16.

FIG. 23 is a partially exploded isometric view of the chassis of FIG. 16with the center tray guide removed.

FIG. 24 is a partially exploded isometric view of the chassis of FIG. 16with the chassis cover removed.

FIGS. 25A and 25B are isometric views of a right tray guide.

FIGS. 26A and 26B are isometric views of a center tray guide.

FIGS. 27A and 27B are isometric views of a left tray guide.

FIG. 28 is an isometric view of a cassette tray.

FIG. 29 is an isometric view of the cassette tray of FIG. 28 with onecassette in the process of being removed from the cassette tray.

FIG. 30 is an isometric view of the cassette tray of FIG. 28 with onecassette further in the process of being removed from the cassette tray.

FIG. 31 is an isometric view of the cassette tray of FIG. 28 with onecassette further in the process of being removed from the cassette tray.

FIG. 32 is an isometric view of a cassette tray with the cassettesremoved.

FIG. 33 is an exploded isometric view of the cassette tray of FIG. 32 .

FIG. 34A is an isometric views of the spring protrusion and portion ofthe cassette tray rail.

FIG. 34B is a partially exploded isometric view of the spring protrusionand cassette tray rail of FIG. 34A.

FIG. 35A is an isometric view of the cassette flex beam and portion ofthe cassette tray rail.

FIG. 35B is a partially exploded isometric view of the cassette flexbeam and cassette tray rail of FIG. 35A.

FIG. 36A is an isometric view of an LC-MPO cassette in an upright firstposition.

FIG. 36B is an isometric view of an LC-MPO cassette in an upside downsecond position.

FIG. 37 is a partially exploded isometric view of an LC adaptercassette.

FIG. 38 is an isometric view of an MPO fiber adapter panel.

FIG. 39 is an isometric view of the MPO fiber adapter panel of FIG. 38and advancing trunk cable furcation leg to be installed into the MPOfiber adapter panel.

FIG. 40 is an isometric view of the MPO fiber adapter panel of FIG. 38with three trunk cable furcation legs fixed between the populationfeature pegs of the MPO fiber adapter panel.

FIG. 41 is a plan view of the MPO fiber adapter panel of FIG. 40 .

FIG. 42 is an isometric view of a chassis applying a unidirectionalpatch cord routing scheme in accordance with an embodiment of thepresent invention.

FIG. 43 is a plan view which illustrates a unidirectional patch cordrouting scheme schematically.

FIG. 44 is an isometric view of a chassis applying a split patch cordrouting scheme in accordance with another embodiment of the presentinvention.

FIG. 45 is a plan view which illustrates a split patch cord routingscheme schematically.

FIG. 46 is an isometric view of the trunk cable management system inaccordance with an embodiment of the present invention.

FIG. 47 is an isometric view of the vertical cable manager.

FIG. 48 is a partial, partially exploded isometric view of the verticalcable manager of FIG. 47 .

FIG. 49 is a partial isometric view of the vertical cable manager ofFIG. 47 .

FIG. 50 is an isometric view of a transition management panel withtransition bundling clips.

FIG. 51 is plan view of the transition bundling clips.

FIG. 52 is an isometric view of a transition management panel withtransition bundling clips installed.

FIG. 53 is a partially exploded isometric view of the transitionmanagement panel of FIG. 52 .

FIGS. 54A and 54B are close-up views of a portion of a transitionbundling clip and a bundling clip fastener.

FIG. 55 is an isometric view of a second embodiment of the trunk cablemanagement system.

FIGS. 56A and 56B are isometric views of the second embodiment of thetransition management panel.

DETAILED DESCRIPTION OF THE INVENTION

The high density fiber enclosure system 2 consists of chassis 100,cassette trays 200, cassette 400, removable unification clip 300, andremovable trunk cable management system 700. The enclosure system 2 maybe made up of several chassis 100 stacked upon each other.

FIG. 1 illustrates the outside of chassis 100 with the front access door140 closed. FIG. 2 illustrates the chassis 100 with the front accessdoor 140 open. FIG. 3 illustrates the chassis 100 with the chassis cover134 removed. FIGS. 1, 2, and 3 also illustrate a slack management plate702 which is mounted to the chassis 100. As shown in FIGS. 2, 3, 4, and5 the chassis 100 may include multiple sliding cassette trays 200. Inthe embodiment shown, there are two cassette trays 200 positionedadjacent to each other in the same row. Further, in the embodimentshown, there are three rows of cassette trays 200. Each cassette tray200 may hold up to two cassettes 400, such that up to a total of sixcassette trays 200 and twelve cassettes 400 may be installed in onechassis 100. Other embodiments are contemplated that may include more orless cassette trays 200 in the same row, and more or less rows ofcassette trays within the chassis.

As shown in FIGS. 4 and 5 , each cassette tray 200 includes multiplecassette tray rails 212, which may slide in and out of chassis 100. FIG.6 illustrates an enhanced view of the front portion of two cassette trayrails 212. FIGS. 7 and 8 illustrate a unification clip 300 connected totwo cassette tray rails 212. A unification clip 300 may be used to jointwo cassette trays 200 together. Unification clip 300 is preferably athree-dimensional C-shaped structure, although unification clip 300 mayalso be D- or O-shaped, or of any other shape which allows unificationclip 300 to join two cassette trays 200 together. As shown in FIGS. 8,9, 10, 11 and 12 , the unification clip 300 has two mounting posts 302,a cable management area 304, a top opening 306, and alignment posts 308.Mounting posts 302 are configured to engage with unification clip slots252 located on the outer cassette tray rail 240 or 242. The mountingposts 302 are located on the rear portion of both sides of unificationclip 300. Cable management area 304 is defined by the lumen of theunification clip 300—i.e. the empty space disposed within theunification clip 300. Alignment posts 308 are located on theforward-most portion of the unification clip 300. Alignment posts 308engage with the front most portion of the cassette tray rails 212 suchthat the cable management area 304 of the unification clip 300 alignswith the front loops 246 of the cassette tray rails 240 or 242. Topopening 306 is disposed at the rear top portion of the unification clip300 and is large enough to allow a patch cable 4 to pass through. Thus,patch cables 4 may be managed by routing them through cable managementarea 304 of unification clip 300. Because the cable management area 304is aligned with the front loop 246 of the cassette tray rails 212 whenthe unification clip 300 is installed, the front loops 246 and cablemanagement areas 304 work together to route patch cables 4. As shown inFIG. 8 , when the unification clip 300 is installed the mounting posts302 of the unification clip 300 each engage unification clip slots 252on different cassette tray rails 212. Similarly, alignment posts 308 ofthe unification clip 300 each engage with different cassette tray rails212, although they engage with the same two cassette tray rails 212 asthe mounting posts 302. In an embodiment, unification clip 300 may beremoved from the cassette tray rails 212 by disengaging the alignmentposts 308 as shown in FIG. 9 . The mounting posts 302 may also bedisengaged as shown in FIG. 10 . FIG. 11 illustrates an isometric viewof the unification clip 300 from the front and FIG. 12 is an isometricview of the unification clip 300 from the back.

FIGS. 13 and 14 illustrate the cassette tray rails 212 in threedifferent positions within a tray guide 104. Cassette tray rails 212 maybe disposed in the same three positions in tray guides 102 and 106. Trayguides 102, 104 and 106 include front, center, and rear detents 120,122, and 124 which serve to position the cassette trays 200 in threeseparate positions—the home position, cord move or change position, andcassette replacement or addition position. Tray guides 102, 104, and 106also each include three tray guide channels 114. FIG. 15 illustrates theinteraction of the spring protrusion 230 of the cassette tray rail 212and the detents 120, 122 and 124 of the tray guides 102, 104, and 106.Spring protrusion 230 comprises a flat piece of flexible material with aprotuberance 256 in its center. The spring protrusion 230 is preferablycomprised of a flexible metal such as steel. The protuberance 256 ofspring protrusion 230 is of a shorter length than detents 120, 122, and124 in the direction of the cassette tray rail 240 or 242 and ispreferably shaped to engage with detents 120, 122, and 124. As shown inFIG. 15 , spring protrusion 230 flexes in the opposite direction of theprotuberance 256 such that, when enough force is applied to slide thecassette tray 200 and the cassette 400 in the forward or rearwarddirection, the protuberance 256 escapes from detents 120, 122, and 124and allows the cassette tray rails 240 or 242 to move freely along trayguides 102, 104, or 106 within tray guide channels 114. When theprotuberance 256 encounters another detent 120, 122, or 124, theprotuberance 256 engages with the detent 120, 122, or 124 and fixes thecassette tray 200 and the cassette 400 in position until enough force isapplied to slide the cassette tray 200 and the cassette 400 to anotherposition.

As further shown in FIGS. 16 and 17 , the chassis 100 also includesforward limiting flanges 116, rear limiting brackets 118, a centerforward limiting bracket 136, a center rear limiting bracket 138, andrack mounting brackets 126. Forward limiting flanges 116 are protrusionson the left and right portions of the chassis 100 disposed proximate tothe forward-most edge of the left tray guide 102 and right tray guide104. The protrusions of the forward limiting flanges 116 are bent 90degrees toward the interior of the chassis 100 to engage with thecassette trays 200 in the cassette replacement or addition position.Rear limiting brackets 118 are brackets disposed or attached proximateto the rearward-most edge of the left tray guide 102, right tray guide104, and center tray guide 106. The rear limiting brackets engage withthe cassette trays 200 in the home position. The center rear limitingbrackets 138 attached to the center tray guide 106 are shaped to engagewith both of the cassette trays 200 located in the same row of thechassis 100 in the home position. The center forward limiting bracket136 is also attached to the center tray guide 106 and is shaped toengage with both of the cassette trays 200 located in the same row ofthe chassis 100 in the cassette replacement or addition position. Oncethe cassette trays 200 are installed within tray guides 102, 104, and106 and the rear limiting brackets 118, center forward limiting bracket136, and center rear limiting bracket 138 are installed on the chassis100, cassette trays 200 are maintained within the chassis 100 and cannotbe removed without first removing the center forward limiting bracket136 or the rear limiting brackets 118 and center rear limiting bracket138.

FIGS. 16 and 17 illustrate the chassis 100 with the cassette trays 200and the cassettes 400 removed. As shown in FIG. 17 , rack mountingbrackets 126 provide the connection between the chassis 100 and the highdensity fiber enclosure system 2. As shown in FIGS. 18 and 19 , the rackmounting brackets 126 may contain two rows of countersink thru holes 128which allow the rack mounting bracket 126 to be adjustably mounted tothe chassis 100. A variety of mounting location options are provided bythe two rows of countersink thru holes 128, allowing the installer toalign the front portion of the chassis 100 with the front portion of thehigh density fiber enclosure system 2. The rack mounting brackets 126also include slotted and cut openings 132 on the top and bottom of theforward-most portion of the rack mounting brackets 126. Notably, theforward-most portion of the rack mounting brackets 126 may be bent 90degrees such that the slotted and cut openings 132 face the front of thechassis 100 when installed. The slotted and cut openings 132 allow thechassis 100 to be pre-installed by allowing the installer to rest thechassis 100 on two pre-installed screws located on the high densityfiber enclosure system 2. The pre-installed screws may then be tightenedto install the chassis 100 in the high density fiber enclosure system 2.

FIG. 20 illustrates an embodiment of the slack management plate 702which includes cutouts 704. Slack management plate 702 may alsooptionally include a divider 726 as shown in FIGS. 1-5 . Divider 726 maybe formed of a removable or permanent wall or other structure disposedperpendicular to the plane of slack management plate 702 which allows auser to organize trunk cable furcation legs 6. One embodiment of divider726 is shown in FIGS. 21A and 21B.

FIG. 22 illustrates the center tray guide 106 removed from the chassis100. Left tray guides 102 and right tray guides 104 are attached to thechassis 100 as shown in FIGS. 22, 23, and 24 . In particular, a lefttray guide 102 is attached to the left side wall 108 of the chassis 100,a right tray guide 104 is attached to the right side wall 110 of thechassis 100. A center tray guide 106 is attached to chassis 100.Alternatively, a center tray guide 106 may be integrally formed suchthat it comprises both a left tray guide 102 and right tray guide 104.Left tray guides 102 and right tray guides 104 are mirror images of oneanother. Each of the tray guides 102, 104 and 106 have three tray guidechannels 114 which serve to support the cassette trays 200 as they slidein and out of the chassis 100.

FIGS. 22-24 further illustrate rear limiting brackets 118 and centerrear limiting brackets 138. Rear limiting brackets 118 are bracketsdisposed or attached proximate to the rearward-most edge of the lefttray guide 102, right tray guide 104, and center tray guide 106. Therear limiting brackets engage with the cassette trays 200 in the homeposition. The center rear limiting brackets 138 attached to the centertray guide 106 are shaped to engage with both of the cassette trays 200located in the same row of the chassis 100 in the home position. Oncethe cassette trays 200 are installed within tray guides 102, 104, and106 and the limiting brackets 118 and 138 are installed on the chassis100, cassette trays 200 are maintained within the chassis 100 and cannotbe removed without first removing the rear limiting brackets 118 and138.

FIGS. 25A and 25B illustrate a right tray guide 104. Right tray guide104 comprises a plurality of tray guide channels 114 running lengthwisedown one side of the tray guide 104 and approximately parallel to oneanother. In one embodiment three tray guide channels 114 comprise aright tray guide 104. Additionally, each tray guide channel 114 includesa front detent 120, a center detent 122, and a rear detent 124 as shownin FIG. 25A.

FIGS. 26A and 26B illustrate a center tray guide 106. Center tray guide106 comprises a plurality of tray guide channels 114 running lengthwisedown both sides of the tray guide 106 and approximately parallel to oneanother. In one embodiment three tray guide channels 114 disposed oneach side of the center tray guide 106 comprise a center tray guide 106.Additionally, each tray guide channel 114 includes a front detent 120, acenter detent 122, and a rear detent 124 as shown in FIG. 26A.

FIGS. 27A and 27B illustrate a left tray guide 102. Left tray guide 102comprises a plurality of tray guide channels 114 running lengthwise downone side of the tray guide 102 and approximately parallel to oneanother. In one embodiment three tray guide channels 114 comprise a lefttray guide 106. Additionally, each tray guide channel 114 includes afront detent 120, a center detent 122, and a rear detent 124 as shown inFIG. 25A. In an embodiment, left tray guides 102 and right tray guides104 are mirror images of one another.

As shown in FIGS. 28, 29, 30, 31, 32 and 33 , each cassette tray 200consists of a tray base 210, cassette tray rails 212, and cassette flexbeam 214. The tray base 210 is preferably comprised of a sheet metalbase. The tray base 210 includes a front recessed area 216 whichprovides maximum allowable reach for an installer or user to accesspatch cords 4 (not shown). The tray base 210 also has a right cassettebay 218 and a left cassette bay 220. Each cassette bay 218 and 220includes a cassette opening 222 which allows an installer to accessinstalled patch cords 4 from the bottom and top of the cassette tray200. Finally, left and right cassette tray rails 240 and 242 aredisposed upon the cassette tray 200 within each cassette bay 218 and 220such that each cassette bay 218 and 220 includes a left cassette trayrail 240 disposed on the left side of the cassette bay 220, and a rightcassette tray rail 242 disposed on the right side of the cassette bay218. Alternatively, if a center cassette tray rail 276 is used, a rightcassette bay 218 may have a cassette tray rail 242 disposed on the rightside of right cassette bay 218 and a center cassette tray rail 276disposed on the left side of right cassette bay 218, and a left cassettebay 220 may have a left cassette tray rail 240 disposed on the left sideof left cassette bay 220 and a center cassette tray rail 276 disposed onthe right side of left cassette bay 220. As further discussed hereinwith reference to the use of the high density fiber enclosure system 2,FIGS. 29-31 show the cassette tray 200 in different stages of removal ofa cassette 400 from the front of the chassis 100.

As shown in FIGS. 32 and 33 , the front patch cord management loop 244is disposed at the forward-most portion of the cassette tray rail 212.The front patch cord management loop 244 provides an organizationstructure for patch cords 4 consisting of a front loop 246 and anopening 248 to route patch cords 4 through. The opening 248 allows thepatch cords 4 to travel from right to left or left to right through thefront loop 246. The front loop 246 has a slot 250 on its topmost portionwhich is wide enough to allow patch cords 4 to pass through. Therefore,patch cords 4 may enter and leave the front loop 246 via the slot 250without either end of the patch cord 4 being disconnected. A unificationclip slot 252 is located just behind the front patch cord managementloop 244 on the cassette tray rail 240 or 242. Unification clip slot 252is located on the outside of the cassette tray rail 240 or 242. Centercassette tray rails 276 do not include unification clip slots 252.Disposed further rearward on the cassette tray rail 212 is the frontpost stop area 234. The front post stop area 234 interacts with thecassette front post 410 to properly seat the cassette 400 into thecassette tray rail 212. Disposed proximate and to the rear of the frontpost stop area 234 is the post stops discontinuity 236. The post stopsdiscontinuity 236 is a smooth portion of the cassette tray rail 212which ensures the front post 410 and rear post 412 of the cassette 400do not engage with the cassette tray rail 212 within the post stopsdiscontinuity 236. Disposed proximate and to the rear of the post stopsdiscontinuity 236 is the rear post stop 238. The rear post stop 238 is anotch designed to interact with the rear post 412 of the cassette 400such that the rear post stop 238 captures the rear post 412 on threesides and blocks the cassette 400 from moving upwards or rearwards.

As further shown in FIGS. 32 and 33 , a cassette centering feature 258is also integrated into the cassette tray rails 212. The cassettecentering feature 258 is a triangular-shaped protuberance located on thebottom portion of the cassette tray rail 212 just proximate to and rearof the front post stop area 234. The cassette centering feature 258 isdesigned such that, when a cassette 400 is loaded from the rear of thechassis 100, an outer shuttered LC adapter 504 or MPO patch cord adapter604 makes contact with the cassette centering feature 258 and, due tothe continued forward movement of the cassette 400, urges the cassette400 into proper alignment with the cassette tray rails 240 or 242 suchthat the front posts 410 engage with the front post stop areas 234 andthe rear posts 412 engage with the rear post stops 238 essentiallysimultaneously.

FIG. 33 illustrates a left cassette tray rail 240, right cassette trayrail 242, and center cassette tray rail 276. The cassette tray rails 212each consist of a support rib 228, spring protrusion 230, front poststop area 234, post stops discontinuity 236, and rear post stop 238.Left cassette tray rails 240 and right cassette tray rails 242 may bemirror images of one another. In an embodiment, a center cassette trayrail 276 consists of a spring protrusion 230, front post stop area 234,post stops discontinuity 236, and rear post stop 238 on both sides ofcenter cassette tray rail 276. In an alternative embodiment, a centercassette tray rail 276 comprises a left cassette tray rail 240 and rightcassette tray rail 242 disposed back-to-back. Center cassette tray rails276 do not include support ribs 228. Left cassette tray rails 240 travelwithin a left tray guide 102 and right cassette tray rails 242 travelwithin a right tray guide 104. The support rib 228 of the cassette trayrail 212 travels along the top portion of a tray guide 102, 104, or 106to support the cassette tray rail 240 or 242 and cassette tray 200. Thesupport rib 228 of the cassette tray rail 240 or 242 extends along thebottom portion of the cassette tray rail 240 or 242 from the rear of thecassette tray rail 240 to 242 to a front patch cord management loop 244.

As shown in FIGS. 13 and 14 , additional features of the cassette trayrail 212 are designed to facilitate the movement of the cassette tray200 and cassette 400 in and out of the high density fiber enclosure 2 inthree different positions. The stopping block 232 interacts with theforward limiting flange 116 to limit forward movement of the cassette400 at the cassette replacement or addition position. The cassettereplacement or addition position is the forward-most disposition of thecassette tray 200 and cassette 400 and allows a user to replace or addcassettes to the chassis 100. The stopping block 232 (as shown in FIGS.34A and 34B) is disposed near the rear of the cassette tray rail 212such that the forward motion of the cassette 400 is halted at thecassette replacement or addition position.

As shown in FIGS. 34A and 34B, a spring protrusion 230 is disposed onthe most rearward portion of the cassette tray rails 240 and 242. Centercassette tray rails 276 do not include spring protrusions 230. Thespring protrusion 230 interferes with the detents 120, 122, and 124 inorder to position the cassette 400 and cassette tray 200 in the home,cord move or change, and cassette replacement or addition positions. Inparticular, the spring protrusion 230 is disposed within the frontdetent 120 at the cassette replacement or addition position. The springprotrusion 230 is disposed within the center detent 122 in the cord moveor change position. Finally, the spring protrusion 230 is disposedwithin the rear detent 124 in the home position. Spring protrusion 230comprises a flat piece of flexible material with a protuberance 256 inits center. The spring protrusion 230 is preferably comprised of aflexible metal such as steel. The protuberance 256 of spring protrusion230 is of a shorter length than detents 120, 122, and 124 in thedirection of the cassette tray rail 240 or 242 and is preferably shapedto engage with detents 120, 122, and 124. As shown in FIG. 15 , springprotrusion 230 flexes in the opposite direction of the protuberance 256such that, when enough force is applied to slide the cassette tray 200and cassette 400 in the forward or rearward direction, the protuberance256 escapes from detents 120, 122, and 124 and allows the cassette trayrails 240 or 242 to move freely along tray guides 102, 104, or 106. Whenthe protuberance 256 encounters another detent 120, 122, or 124, theprotuberance 256 engages with the detent 120, 122, or 124 and fixes thecassette tray 200 and cassette 400 in position until enough force isapplied to slide the cassette tray 200 and cassette 400 to anotherposition.

As shown in FIGS. 35A and 35B, cassette flex beam 214 is formed of abeam shaped to engage with the cassette 400 such that the cassette 400is securely installed in the cassette tray 200 and no unwanted motion ofthe cassette 200 within the cassette tray 400 occurs. Left cassette flexbeams 260 are disposed on left cassette tray rails 240; right cassetteflex beams 262 are disposed on right cassette tray rails 242. Leftcassette flex beams 260 are mirror images of right cassette flex beams262. Cassette flex beam 214 has a beam portion 264, catch wall 266,front lead-in 268, and mounting hole 270. The beam portion 264 ofcassette flex beam 214 is disposed between the catch wall 266 andmounting hole 270 and is generally horizontal. The catch wall 266 ofcassette flex beam 214 is disposed on the rear-most portion of the beamportion 264 and is generally vertical. The catch wall 266 includes adivot 272 which is shaped to engage with front post 410 of the cassette400 such that catch wall 266 prohibits the cassette 400 from upwardmovement until sufficient upward force is applied to the cassette 400 todeflect the flex beam 214. Catch wall 266 also applies rearward pressureon the front post 410 of the cassette 400 to minimize rattling or otherunwanted movement while the cassette 400 is in an installed position.Front lead-in 268 is a portion of the catch wall 266 which protrudesrearwardly from the rest of catch wall 266. Front lead-in 268 guides thefront post 410 of the cassette 400 into the divot 272 during frontcassette installation. Front lead-in 268 also forms the top portion ofdivot 272. Mounting hole 270 is disposed on the front-most portion ofthe beam portion 264 of cassette flex beam 214. Mounting hole 270 isconfigured to mount the flex beam 214 on the cassette tray rail 240 or242 when the flex beam 214 is assembled with the cassette tray rail 212.Cassette flex beam 214 may also be integrally formed with a cassettetray rail 212. If cassette flex beam 214 is integrally formed withcassette tray rail 212, mounting hole 270 is not necessary.

Two different types of cassettes 400 are disclosed for use with the highdensity fiber enclosure system 2, an LC-MPO cassette 500 (FIGS. 36A, 36Band 37 ) and an MPO fiber adapter panel (“herein after “MPO FAP”) 600(FIGS. 38, 39, 40, and 41 ), although other types of cassettes 400 mayalso be used. Cassettes 400 used with the high density fiber enclosuresystem 2 may have a cassette body 406, a cassette cover 408, cassettefront posts 410, cassette rear posts 412, cassette rear post releaselatches 414, and cassette rear release latch stops 416. Cassette body406 is of generally rectangular shape, and has a base 418, right side420, and left side 422. Right and left sides 420 and 422 have a rightwall 424 and left wall 426, respectively, and are attached at agenerally 90 degree angle to base 418 at the right and left sides 420and 422 of base 418. A cassette cover 408 is provided which extendsparallel to the base 418 of the cassette body 406 from the right wall424 to the left wall 426. Cassette cover 408 is provided to protect thecomponents of cassette 400. Cassette 400 may also include top sideindicator 428 and bottom side indicator 430. Top side indicator 428 isdisposed on the outside portion of cassette cover 408 and indicatesthat, when visible as viewed from above an installed cassette 400, thecassette 400 is disposed in an upright first position (see FIG. 36A).Bottom side indicator 430 is disposed on the outside portion of cassettebody 406 and indicates that, when visible as viewed from above aninstalled cassette 400, the cassette 400 is disposed in an upside downsecond position (see FIG. 36B). Top side indicator 428 and bottom sideindicator 430 may be comprised of raised embossing, a plate or labelattached to the cassette 400, a painted area, or any other form ofmarking. Top side indicator 428 and bottom side indicator 430 may be aword, number, phrase, symbol, or combination thereof sufficient toinform the user whether the cassette 400 is in the upright firstposition or upside down second position. Alternatively, a recess 436 maybe provided on the top and bottom sides of cassette 400 to allow a usera location to affix his or her own label to both sides of cassette 400.Recess 436 may be of any shape, but is preferably of a rectangularshape.

As described above, cassette front posts 410 are designed to interactwith the cassette tray rail front post stop areas 234 such that at theinstalled position, the cassette front posts 410 rest inside thecassette tray rail front post stop areas 234 and are blocked fromforward movement by a catch wall 266 of cassette flex beam 214 locatedin the cassette tray rail front post stop area 234. Cassette rear posts412 are designed to interact with the cassette tray rail rear post stops238 in the cassette installed position. At the cassette installedposition the cassette rear posts 412 are maintained inside the cassettetray rail rear post stops 238 blocking rearward and upward movement ofthe cassette 400.

Shown in FIGS. 36A, 36B, 37, 38, 39, 40, and 41 , cassette rear postrelease latches 414 are designed to disengage the cassette rear posts412 from the cassette tray rail rear post stops 238 when a user desiresto uninstall a cassette 400. Cassette rear post release latches 414 arepreferably comprised of a protrusion 432 from the rear of cassette rearpost 412 and an opening 434 between the body of the cassette 400 and therear post 412. Cassette rear post release latches 414 are comprised of aresilient material which allows the rear post 412 to flex inwardly whenpressure is placed on cassette rear post release latches 414. When auser desires to uninstall a cassette 400, the user places inwardlydirected pressure on cassette rear post release latch 414. The cassetterear post 412 then travels inwardly and disengages with the cassettetray rail rear post stop 238. Cassette 400 may then be removed from thecassette tray 200. Cassette rear post release latch stop 416 is disposedon the body of the cassette 400 in a position to engage with thecassette rear post release latch 414 when inwardly directed pressure isplaced on cassette rear post release latches 414. The cassette rear postrelease latch stop 416 is positioned to allow the cassette rear post 412to travel a sufficient distance in the inward direction to disengagefrom the cassette tray rail rear post stop 238 while blocking thecassette rear post 412 from over traveling in the inward direction.Blocking over travel of cassette rear post 412 in the inward directionmay minimize unnecessary material fatigue and/or the failure of cassetterear post release latch 414, prolonging the useable life of cassette400. Cassette rear post release latch stop 416 may be comprised of apost or other protrusion extending from the body of the cassette 400.Alternatively, cassette rear post release latch stop 416 may be part ofthe body of the cassette 400.

As noted above, at least two different types of cassettes 400 may beused in the high density fiber enclosure system 2—LC-MPO cassettes 500(FIGS. 36A, 36B and 37 ) and MPO FAP 600 (FIGS. 38, 39, 40, and 41 ). Inaddition to the cassette features described above, LC-MPO cassettes 500also include a front LC mounting face 502, shuttered LC adapters 504,rear MPO mounting window 506, and an MPO trunk adapter 508. The front LCmounting face 502 is located on the front portion of LC-MPO cassette 500and provides a location for mounting shuttered LC adapters 504.Shuttered LC adapters 504 are standard adapters known and used in theart for connecting patch cords 4 within data management centers, forexample, shuttered LC adapters. Alternatively, for example, shuttered LCadaptors or non-shuttered LC adaptors may be used. Front LC mountingface 502 provides space for up to 6 shuttered LC adapters 504. MPO trunkadapter 508 is located at the rear of cassette body 406 and connects totrunk cable furcation legs 6 which each include a dust cap 16. Dust caps16 are removed from trunk cable furcation legs 6 prior to installationof trunk cable furcation legs 6 in MPO trunk adapters 508. MPO trunkadapters 508 are standard adapters known in the art, for examplePanduit's SC style simplex form adapter. Rear MPO mounting windows 506are located on the rear portion of cassette body 406 and each provide alocation on the cassette body 406 for mounting MPO trunk adapters 508 tothe cassette body 406. In one embodiment, four MPO mounting windows 506are located on the cassette body 406 which allows up to four MPO trunkadapters 508 to be mounted on cassette body 406.

As an alternative to LC-MPO cassettes 500 (or other types of cassettes400), MPO FAP 600 may be used as shown in FIGS. 38, 39, 40, and 41 . Inaddition to the cassette features described above, MPO FAP 600 alsoinclude a front MPO mounting face 602, MPO patch cord adapters 604,bottom window 608, and population feature 610. Front MPO mounting face602 is located on the front portion of cassette body 406 and provides alocation for mounting up to six MPO patch cord adapters 604. MPO patchcord adapters 604 are configured to connect patch cords 4 with thecassette 600. Up to six MPO patch cord adapters 604 provide a locationfor connecting up to six trunk cable furcation legs 6 which each have adust cap 16. Dust cap 16 is removed from trunk cable furcation legs 6prior to installing trunk cable furcation legs 6 into MPO patch cordadapters 604. Bottom windows 608 are disposed on the cassette body base418 just behind the front MPO mounting face 602. Bottom windows 608allow a user to access the MPO trunk cable furcation legs 6 from the topand bottom to allow a user to connect or disconnect trunk cablefurcation legs 6 to and from MPO trunk adapters 604.

As shown in FIGS. 38-41 , population feature 610 provides a trunk cablefurcation legs 6 capture and routing system for installing, adding, orchanging trunk cable furcation legs 6 attached to MPO trunk adapters 604in an MPO FAP 600. Population feature 610 is comprised of a plurality ofrows of offset pegs 612 disposed on the base 418 of the MPO FAP 600.Pegs 612 may be of any shape, including cylindrical, triangular,rectangular, etc. Preferably, three to four pegs 612 are provided ineach row. When installing a trunk cord 6, the user routes the trunkcable furcation legs 6 through the rows of pegs 612. The offset natureof the rows of pegs 612 loosely holds the trunk cable furcation legs 6in position while cassette 600 is translated via the movement of thecassette tray 200 to the cassette remove or addition position. Oncecassette tray 200 is in the cassette remove or addition position, theMPO connector 8 is disengaged from the pegs 612 and trunk cablefurcation legs 6 are extended to reach the MPO trunk adapters 604, atwhich point the MPO connector dust cap 16 may be removed. Then the trunkcable MPO Connectors 8 are connected to MPO trunk adapters 604; thetrunk cable furcation legs 6 may remain routed through the rows of pegs612.

FIGS. 42, 43, 44, and 45 illustrate multiple embodiments of cablemanagement within the cassette trays 200. FIG. 42 illustrates aunidirectional cable management scheme in which the patch cables 4 arerouted through the front patch cord management loops 244 in onedirection. As shown in FIGS. 42 and 43 , a unification clip 300 istypically installed when using a unidirectional scheme. FIG. 43illustrates an overhead view of cable flow as shown in FIG. 42 . FIG. 44illustrates a split routing cable management scheme in which the patchcables 4 are routed through the front patch cord management loops 244 intwo separate directions. Specifically, as shown in FIG. 44 , the patchcables 4 exiting a cassette tray 200 installed on the left side of achassis 100 are routed to the left of the chassis 100, and patch cables4 exiting a cassette tray 200 installed on the right side of a chassis100 are routed to the right side of the chassis 100. FIG. 45 illustratesan overhead view of cable flow shown in FIG. 44 .

As illustrated in FIG. 46 , the high density fiber enclosure system 2may also include a trunk cable management system 700. The trunk cablemanagement system 700 includes a slack management plate 702 and avertical cable manager 708.

As illustrated in FIG. 46 (as well as FIGS. 1-5 ), the slack managementplate 702 is mounted to a chassis 100 by attaching the front mostportion of the slack management plate 702 to the rear most portion ofthe left and right side walls of the chassis 108 and 110 using springloaded fasteners 706 and support pin 724 (shown in FIG. 20 ). Thesupport pin 724 is connected to the slack management plate 702 such thatthe slack management plate 702 may be rotated about the support pin 724.The spring loaded fasteners 706 secure the slack management plate 702 tothe left and right side walls of the chassis 108 and 110. The slackmanagement plate 702 provides a relatively level surface upon which theportion of trunk cable furcation legs 6 which exit the chassis 100 mayrest to reduce the strain upon the trunk cable furcation legs 6. Inaddition, the slack management plate 702 allows for management of trunkcable furcation legs 6 slack which is adequate to allow full extensionof cassette trays 200 to further reduce the strain upon the trunk cablefurcation legs 6. The slack management plate 702 preferably includescutouts 704 which allow the pins, fasteners, separators, cable ties,and/or other features for removably and securely organizing the trunkcable furcation legs 6 as they rest upon the slack management plate 702.Cutouts 704 may be of any shape, but as shown in FIGS. 1-5 they arepreferably of a square or rectangular shape. Preferably the trunk cablefurcation legs 6 installed on one cassette 400 may be disposed on oneside of divider 726 and the trunk cable furcation legs 6 installed inthe other cassette 400 may be disposed on the other side of divider 726.A slack management plate 702 is preferably mounted to each chassis 100.

As shown in FIGS. 46, 47 and 48 , the vertical cable manager 708 ismounted to the side of the high density fiber enclosure system 2 andprovides structure for organizing and reducing the strain upon the trunkcables 14 and trunk cable furcation legs 6. The vertical cable manager708 consists of transition management panels 710 with attachment points712 and panel attachment clips 714, cable management fingers 716, andtransition bundling clips 718 with transition indentations 720 andbundling clip fasteners 722. As shown in FIG. 49 , transition managementpanels 710 are mounted on the trunk cable management system 700 suchthat they are generally perpendicular and offset to the slack managementplates 702. The transition management panels 710 include attachmentpoints for transition bundling clips 712. As shown in FIG. 52 ,attachment points for transition bundling clips 712 are slots configuredwithin the transition management panels 710 such that transitionbundling clips 718 securely engage transition management panels 710, orallow pins, fasteners, separators, cable ties, and/or other features forremovably and securely organizing the trunk cables 14 or trunk cabletransitions 20. A plurality of attachment points 712 are preferablydisposed on each transition management panel 710, and attachment points712 are preferably arranged in a number of rows of multiple attachmentpoints 712 such that transition bundling clips 718 may be attached in astaggered fashion to transition management panel 710. Panel attachmentclips 714 are generally located at each corner of generally rectangularshaped transition management panels 710 and are configured such that thetransition management panels 710 are securely affixed to cablemanagement fingers 716.

As shown in FIGS. 47, 48, and 49 , cable management fingers 716 protrudefrom the vertical cable manager 708 toward the front and rear of chassis100. The cable management fingers 716 preferably include a perpendicularportion at the end of the fingers 716 furthest from chassis 100 to moresecurely confine cables. Transition management panels 710 are preferablymounted upon cable management fingers 716 such that each panelattachment clip 714 of each transition management panel 710 is disposedon a different cable management finger 716. The transition managementpanels 710 can be secured to the cable management fingers 716 at anypoint along the length of the cable management fingers 716, which allowsa user to stagger the cable management panels 710 such that sometransition management panels 710 are located closer to the verticalcable manager 708 than other transition management panels 710. Thisallows a greater number of trunk cables 14 and trunk cable furcationlegs 6 to be better managed in a smaller area with less strain to thetrunk cables 14.

As shown in FIGS. 47, 48, 49, and 50 transition bundling clips 718 aremounted upon transition management panels 710 via attachment points 712.As shown in FIG. 51 , transition bundling clips 718 include a transitionindentation 720. The transition indentation 720 is preferably disposedwithin trunk cable transition 20 between trunk cables 14 and trunk cablefurcation legs 6 such that the trunk cable transition 20 is securelyhoused within transition indentation 720 and strain upon the transitionis reduced or eliminated.

As shown in FIGS. 52 and 53 , panel attachment clips 714 are preferablyone of two types of clips—snap fit panel attachment clips 728 or loosefit panel attachment clips 730. Preferably two snap fit panel attachmentclips 728 are located on one side of transition management panels 710and two loose fit panel attachment clips 730 or snap fit panelattachment clips 728 are located on the other side of the transitionmanagement panel 710. As shown in FIGS. 54A and 54B, bundling clipfasteners 722 engage the transition bundling clips 718 and transitionmanagement panels 710 to securely affix the transition bundling clips718 to a transition management panel 710.

In another embodiment for managing trunk cables 14, trunk cablefurcation legs 6, trunk cable transition 20, shown in FIG. 55 ,transition management panels 710 a may be mounted upon the rackequipment rails 18 of the high density fiber enclosure system 2. Asshown in FIGS. 56A and 56B, transition management panels 710 a includeattachment points 712 as well as slotted and cut openings 714 a forsecuring the transition management panels 710 a directly to the rackequipment rails 18. Transition management panels 710 a may be mountedupon the rack equipment rails 18 of the high density fiber enclosuresystem 2 such that the transition management panels 710 a extend alongthe side of the high density fiber enclosure system 2 or along the rearportion of high density fiber enclosure system 2. The user may securethe trunk cable transitions 20 between trunk cables 14 and trunk cablefurcation legs 6 using transition bundling clips 718 which are mountedupon transition management panels 710 a via attachment points 712 andsecured with bundling clip fasteners 722. Alternatively, the user maysecure the trunk cable transitions 20 upon transition management panels710 a through attachment points 712 with fasteners known in the art, forexample hook and loop tape.

Use of the above features of the high density fiber enclosure system 2will now be described.

To connect a chassis 100 to a high density fiber enclosure system 2, auser connects a rack mounting bracket 126, for example as shown in FIGS.17, 18 and 19 , to the chassis 100 via the countersink thru holes 128with a chassis screw 130. Several rows of countersink thru holes 128 areprovided to allow the user to select the appropriate countersink thruhole 128 that results in the alignment of the front of the chassis 100with the front of the high density fiber enclosure system 2 in theinstalled position. The user inserts the chassis screw 130 into thecountersink thru hole 128 and into the chassis 100 to attach themounting bracket 126.

To mount the chassis 100 to the high density fiber enclosure system 2,for example as shown in FIG. 46 , the user pre-installs screws into theretainment holes 10 disposed on the high density fiber enclosure system2 without fully tightening the screws. The user hooks the rack mountingbracket 126 onto the pre-installed screws via the slotted and cutopenings 132, as shown in FIGS. 18 and 19 for example, and allows thechassis 100, which is attached to the mounting bracket 126, to rest in agenerally horizontal position on the slotted and cut openings 132. Oncethe chassis 100 is in the desired position, the user then tightenspre-installed screws to secure the chassis 100 into the high densityfiber enclosure system 2.

A user may load cassettes 400 into the cassette trays 200 of the chassis100 from either the rear or front of the chassis 100. To load a cassette400 into the chassis 100 from the rear of the chassis 100, a user mayinsert the cassette 400 into a right or left cassette bay 218 or 220,for example as shown in FIG. 28 , with the front portion of the cassette400—i.e. the portion of the cassette 400 nearest the cassette frontposts 410—loaded into the cassette bay 218 or 220 first. Cassette frontposts 410 are narrower than cassette rear posts 412 and therefore do notengage the rear post stops 238 as they pass the rear post stops 238. Theuser may advance the cassette 400 into the cassette bay 218 or 220 untilthe cassette rear post 412 engages with the rear post stops 238. Whenthe cassette rear post 412 engages with the rear post stops 238, thecassette 400 cannot be advanced further into cassette bay 218 or 220. Atthe same time the cassette rear posts 412 engage the rear post stops238, the cassette front posts 410 engage with the catch wall 266 of thecassette flex beam 214. The catch wall 266 of the cassette flex beam 214holds the cassette front posts 410 such that they cannot be advancedfurther with respect to the cassette bay 218 or 220. The catch wall 266of the cassette flex beam 214 may apply rearward pressure on thecassette front post 410 to insure the cassette rear posts 412 aresecurely engaged with rear post stops 238 and the cassette 400 does notrattle or otherwise move unintentionally. The user then may connectpatch cords 4 and trunk cable furcation legs 6 to the cassette 400 asnecessary. The user may also then route patch cords 4 and trunk cablefurcation legs 6 as described below. Alternatively, the user may installtrunk cable furcation legs 6 into the cassette 400 prior to loadingcassette 400 into cassette bay 218 or 220.

To load a cassette 400 from the front of the high density fiberenclosure 2, a user first advances the cassette tray 200 to the cassetteaddition or replacement position as described below. The user theninserts the cassette 400 into a right or left cassette bay 218 or 220,for example as shown in FIGS. 28 and 29 , from the front of the chassis100 with the rear portion—i.e. the portion of the cassette nearest thecassette rear posts 412—loaded into the cassette bay 218 or 220 first byplacing the rear of the cassette 400 on the base 210 of the cassettetray 200 such that the cassette rear posts 412 are located between thefront post stop areas 234 and rear post stops 238 of the cassette trayrails 212. The cassette 400 is slightly tilted upward such that thefront portion of the cassette 400 is higher than the rear portion of thecassette 400. The user then advances the cassette 400 in the rearwarddirection, maintaining the tilt of the cassette 400 as the front portionof the cassette 400 is in a somewhat higher position than the rearportion of the cassette 400, until the rear posts 412 engage with therear post stops 238. By maintaining the front portion higher than therear portion of the cassette 400, contact with other equipment isminimized. The cassette 400 should clear any patch cords 4 that areconnected to other cassettes 400 installed in the chassis 100 and routedthrough the cassette tray rail patch cord management loops 244. Once therear posts 412 are seated against the rear post stops 238, the userapplies downward pressure to the cassette 400 in the region of frontposts 410. As downward pressure is applied, the cassette flex beam 214flexes to allow front posts 410 to slip past the front lead-in 268 ofthe catch wall 266 and into engagement with the catch wall 266 of thecassette flex beam 214. The user then may connect patch cords 4 andtrunk cable furcation legs 6 to the cassette 400 as necessary as well asroute patch cords 4 and trunk cable furcation legs 6 as described below.Alternatively, a user may connect patch cords 4 prior to applyingdownward pressure to the cassette 400 to seat the front posts 410.

A user may also unload cassettes 400 from the cassette trays 200 of thechassis 100 from either the rear or front of the chassis 100. To unloadcassettes 400 from the rear of the chassis 100, a user first disconnectsthe patch cords 4 from the front of the chassis 100, and thendisconnects trunk cable furcation legs 6 from the rear of the chassis100. The user then locates and applies inward pressure to the rear postrelease latches 414 on the cassette 400, for example as shown in FIGS.36A, 36B, 37, 38, 39, 40, and 41 . As inward pressure is applied to therear post release latches 414, the latches 414 flex and rear posts 412disengage with the rear post stops 238. As the user continues to applyinward pressure to the rear post release latches 414, the user pulls thecassette 400 toward the rear of the chassis 100 until the cassette 400clears the chassis 100.

FIGS. 29, 30, and 31 illustrate unloading cassettes 400 from the frontof chassis 100. To unload cassettes 400 from the front of the chassis100, a user may first position the cassette tray 200 in the cassetteaddition or replacement position as described below. A user thendisconnect patch cords 4 from the front of the chassis 100. The user maythen apply upward pressure on the front portion of cassette 400 near thefront posts 410, accessing cassette 400 through the cassette opening222. The user applies enough upward pressure on the cassette 400 tocause the flex beam 214 to flex enough to allow front posts 410 to passby the divot 272 of the catch wall 266 of the flex beam 214. Once thefront posts 410 have cleared the front lead-in 268 of the catch wall 266of the flex beam 214, the cassette 400 is tilted such that the frontportion of the cassette 400 is higher than the rear portion of thecassette 400 as shown in FIG. 29 . A user may then pull the cassette 400toward the front of the chassis 100 until the cassette 400 clears thechassis 100, generally maintaining the tilt of cassette 400, as shown inFIG. 30 . Once the trunk cable furcation legs 6 and MPO trunk adapters508 or MPO FAP patch cord adapters 604 at the rear of cassette 400 arevisible, a user may disconnect trunk cable furcation legs 6 from the MPOtrunk adapters 508 or MPO FAP patch cord adapters 604 and cassette 400.As shown in FIG. 31 , a user then preferably removes the cassette 400 bypositioning the cassette 400 such that the rear posts 412 are level withfront posts 410 so that the cassette 400 should clear any patch cords 4that are connected to other cassettes 400 installed in the chassis 100and routed through the cassette tray rail patch cord management loops244, as described below.

A user may also replace an LC-MPO cassette 500 with an MPO FAP 600.First, a user may follow the procedures for removing a cassette 400above in order to remove the LC-MPO cassette 500. Next the user mayconnect the trunk cable furcation legs 6 to an MPO trunk adapter 604,and insert the new MPO FAP 600 following the instructions forinstallation of a cassette 400 from the front of the chassis 100 above.If the user desires to add additional trunk cable furcation legs 6 tothe MPO FAP 600 (which allows for up to five additional trunk cablefurcation legs 6 to attach to five additional MPO trunk adapters 604),the user may route the additional trunk cable furcation legs 6 throughthe rear of the cassette bay 218 or 220 into the MPO FAP 600 from therear of the chassis 100. As discussed above, for example with referenceto FIGS. 38-41 , MPO FAP 600 includes a population feature 610consisting of a plurality of offset rows of population feature pegs 612.After routing the additional trunk cable furcation legs 6, upon whichdust caps 16 are installed, into the rear of the cassette 600, the usermay trap the MPO connectors 8 of the trunk cable furcation legs 6between the population feature pegs 612, by inserting the MPO connector8 diagonally through the open path created by the offset rows of thepopulation feature 610 and placing the trunk furcation leg 6 on theopposite side of the peg 612 located at the rear most section of the MPOFAP 600 as shown in FIG. 40 . The population feature pegs 612 maytherefore temporarily lock the trunk cable furcation legs 6 in position,allowing the user to advance the cassette tray 200 to the cassetteaddition or replacement position described below. Because the trunkcable furcation legs 6 are locked into the population feature 610 of theMPO FAP 600, they are secured from falling out of the rear of thechassis 100 and instead are pulled forward along with the MPO FAP 600.Once the cassette 600 is in the cassette addition or replacementposition the user may reach into the MPO FAP 600, remove the dust caps16, and attach the additional trunk cable furcation legs 6 to anyavailable MPO trunk adapters 604. The user may then add and route anyadditional patch cords 4 as needed, and return the MPO FAP 600 to thehome position.

As discussed above with reference to FIGS. 13, 14 and 15 , for example,the tray guides 102, 104, and 106 include three detents, a front detent120, center detent 122, and rear detent 124. The cassette chassis 100also includes forward limiting flanges 116 and rear limiting brackets118. Each of these features interacts with features of the cassette tray200 to facilitate movement of the cassette tray 200 between threedifferent positions—the home position, cord move or change position, andcassette replacement or addition position. In the home position, shownin FIG. 14 , the protuberance 256 of the spring protrusion 230 isdisposed within the rear detent 124. Additionally, the rearmost portionsof the cassette tray rail support ribs 218 abut against the rearlimiting brackets 118, thereby blocking any further rearward movement ofthe cassette tray 200.

In the patch cord move add or change position, the protuberance 256 ofthe spring protrusion 230 is located within the center detent 122, asshown in FIG. 14 . In order to advance the cassette tray 200 from thehome position, a user applies sufficient force toward the front of thechassis 100 to cause the spring protrusion 230 to flex and allow theprotuberance 256 to escape from the rear detent 124. The user thencontinues to apply force toward the front of the chassis 100 until theprotuberance 256 reaches the center detent 122, at which point theprotuberance 256 interacts with the center detent 122, stopping theforward motion of the cassette tray 200.

If the user wishes to advance the cassette tray 200 to the cassettereplacement or addition position, the user applies sufficient forcetoward the front of the chassis 100 to cause the spring protrusion 230to flex and allow the protuberance 256 to escape from the center detent122. The user then continues to apply force toward the front of thechassis 100 until the protuberance 256 reaches the front detent 120. Atthe same time the protuberance 256 reaches the front detent 120, thecassette tray 200 also engages with the forward limiting flanges 116 toblock further forward movement of the cassette tray 200. In order tomove the cassette tray 200 from the cassette replacement or additionposition to either the home or patch cord move add or change positions,a user applies rearward force to the cassette tray 200 until theprotuberance 256 reaches the center detent 122 for the patch cord moveadd or change position or the rear detent 124 for the home position.

A user may install a unification clip 300 to secure two adjacentcassette trays 200 in the same chassis 100 together such that they areadvanced out of and retracted into the chassis 100 at the same time. Inorder to install the unification clip 300, a user may first advance thecassette trays 200 to the patch cord move add or change position, asshown in FIG. 13 . As shown in FIGS. 9 and 10 , a user may then insertthe mounting posts 302 of the unification clip 300 into the unificationclip slot 252 located on each cassette tray rail 212 such that the cablemanagement area 304 of the unification clip 300 is disposed above andbetween the front patch cord management loops 244 of the cassette trays200 that are being joined together. The user may then apply downwardpressure to the unification clip 300 to cause the alignment posts 308 ofthe unification clip 300 to engage the top of the front-most portion ofthe cassette tray rails 240 or 242 to secure the unification clip 300 tothe cassette trays 200 as well as align the cable management area 304 ofthe unification clip 300 with the front patch cord management loops 244of the cassette trays 200. The joined cassette trays 200 may then bereturned to the home position as one unit.

There are two preferred methods of routing patch cables 4 as they exitthe front of the chassis 100, a split routing scheme method (for exampleas shown in FIGS. 44 and 45 ) and a unidirectional routing scheme method(for example as shown in FIGS. 42 and 43 ). The split routing schememethod may be used when a unification clip 300 is not installed. To usethe split routing scheme, a user may insert patch cords 4 into the frontpatch cord management loop 244 by slipping the cords through the frontpatch cord management loop slot 250. The patch cords 4 attached to thecassette 400 installed in the left cassette tray 200 are routed throughthe left-most front patch cord management loop 244, while the patchcords 4 attached to the cassette 400 installed in the right cassettetray 200 are routed through the right-most front patch cord managementloop 244. This arrangement allows each cassette tray 200 to be movedbetween the home, cord move or change, and cassette replacement oraddition positions without disturbing the patch cords 4 attached to thecassettes 400 installed in the other cassette tray 200 contained in thesame row as the moving cassette tray 200.

To route the patch cables using a unidirectional routing scheme, a userfirst installs the unification clip 300. The user then routes the patchcords 4 by routing them to the right or left of the chassis 100. Theuser may then insert each patch cord 4 into the front patch cordmanagement loops 244 and/or the cable management area 304 of theunification clip 300 as the cords 4 pass by the front patch cordmanagement loops 244 and/or the cable management area 304. The userinserts the patch cords 4 into the front patch cable management loops244 by slipping the cords 4 through the front patch cord management loopslot 250. The user inserts patch cords 4 into the cable management area244 of the unification clip 300 by slipping the cables 4 into the cablemanagement area 304 via the top opening 306 of the unification clip 300.Because the patch cables 4 are routed in the same direction for bothcassette trays 200 and the cassette trays 200 are joined together withthe unification clip 300, both cassette trays 200 move between the home,cord move or change, and cassette replacement or addition positionssimultaneously.

What is claimed is:
 1. A fiber enclosure comprising: a chassisconfigured to house a plurality of cassettes; a first tray guide securedto the chassis, the first tray guide including a plurality of firstdetents; a second tray guide secured to the chassis, the second trayguide including a plurality of second detents; a cassette trayconfigured to move between the first tray guide and the second trayguide, the cassette tray comprising: a first rail having a continuouslength extending from a rear end and a front end of the first rail, thefirst rail configured to move within the first tray guide, the firstrail including a first stopping member configured to engage with theplurality of first detents included in the first tray guide, the firstrail further including a first routing member comprising the front endof the first rail wherein the first routing member is configured toroute a cable at a front end of the fiber enclosure; a second railconfigured to move within the second tray guide, the second railincluding a second stopping member configured to engage with theplurality of second detents included in the second tray guide; a traybase; and a third rail configured to be removably attached to the traybase between the first rail and the second rail.
 2. The fiber enclosureof claim 1, wherein at least one of the first rail or the second railincludes a unification clip slot configured to receive a unificationclip.
 3. The fiber enclosure of claim 1, wherein the third rail includesa third routing member configured to route a cable at a front end of thefiber enclosure.
 4. The fiber enclosure of claim 1, wherein the firststopping member and the second stopping member are a flexible metalspring.
 5. The fiber enclosure of claim 1, further comprising: a slackmanagement plate configured to manage slack in a cable installed intothe fiber enclosure, the slack management plate configured to beremovably attached to a rear of the chassis by at least onespring-loaded fastener.
 6. The fiber enclosure of claim 1, furthercomprising: a slack management plate configured to manage slack in acable installed into the fiber enclosure, the slack management plateconfigured to be removably attached to a rear of the chassis and theslack management plate includes at least one fastener configured toremovably secure the slack management plate to be substantially levelrelative to the chassis.
 7. The fiber enclosure of claim 1, furthercomprising: a slack management plate; a divider; and a plurality ofopenings on each of a first side and a second side of the divider forremovably attaching the divider at different locations on the slackmanagement plate.
 8. The fiber enclosure of claim 1, further comprising:a slack management plate; a divider disposed perpendicular to a plane ofthe slack management plate; and a plurality of openings on each of afirst side and a second side of the divider for removably attaching thedivider at different locations on the slack management plate.
 9. Thefiber enclosure of claim 1, further comprising a slack management plate,the slack management plate comprising: a first side wall configured tobe rotatably attached to a first side wall of the chassis by a firstsupport pin; and a second side wall configured to be rotatably attachedto a second side wall of the chassis by a second support pin.
 10. Thefiber enclosure of claim 1, wherein the plurality of first detentsinclude at least three detents and the plurality of second detentsincludes at least three detents.
 11. The fiber enclosure of claim 1,further comprising: at least three layers of the first tray guidestacked on top of each other; and at least three layers of the secondtray guide stacked on top of each other.
 12. The fiber enclosure ofclaim 1, wherein: the first rail further comprising a first rear poststop configured to prevent a cassette installed into the cassette trayusing the first rail from further moving past the first rear post stop;and the second rail further comprising a second rear post stopconfigured to prevent a cassette installed into the cassette tray usingthe second rail from further moving past the second rear post stop. 13.The fiber enclosure of claim 1, wherein: the first rail furthercomprising a first front post stop configured to interact with a frontpost of a cassette to assist seat the cassette into the cassette trayusing the first rail; and the second rail further comprising a secondfront post stop configured to interact with a front post of a cassetteto assist seat a cassette into the cassette tray using the second rail.14. The fiber enclosure of claim 1, the second rail having a continuouslength extending from a rear end and a front end of the second rail, thesecond rail further including a second routing member comprising thefront end of the second rail wherein the second routing member isconfigured to route a cable at the front end of the fiber enclosure.